1. Field of the Invention
This invention relates to a cleaning blade member, and more particularly, to a cleaning blade member for removing a toner on a toner image bearing body, on which a toner image is formed and from which the toner image is transferred onto a material for receiving the toner image, such as a photoconductor or a transfer belt in electrophotography.
2. Description of the Related Art
With the electrophotographic process, a cleaning blade for removing a toner is generally used to use an electrophotographic photoconductor or a transfer belt repeatedly. Since the cleaning blade makes contact with the photoconductor for a long term, it is required to have satisfactory wear resistance and a low coefficient of friction. In recent years, as the life of the unit lengthens, the photoconductor has become a product with high durability, and the cleaning blade has also been required to have high durability.
To impart high durability to the blade, it is necessary for the blade to have a high degree of hardness. However, a high degree of hardness of the cleaning blade of a single-layer structure leads to too high a pressure of contact with the photoconductor, posing the problem that a film on the surface of the photoconductor peels off, or the edge of the blade droops. That is, when the blade is supported horizontally in a cantilevered manner at an end portion thereof on the side opposite to its side in contact with the photoconductor, the height of the leading end of the blade decreases. Thus, proposals have been made for cleaning blades each having a plural-layer structure (see, for example, Japanese Patent No. 2542204, Japanese Unexamined Patent Publication No. 2002-214989, and Japanese Unexamined Patent Publication No. 2002-214990).
Since these cleaning blades use plural types of materials, a layer in contact with the photoconductor, and other layers make up for each other's characteristics, thereby showing excellent characteristics as a whole. However, they exhibit satisfactory characteristics in either a high temperature environment or a low temperature environment, and do not show satisfactory characteristics in an environment at high temperatures to low temperatures.
Hence, there has been an intense demand for a cleaning blade which maintains sufficiently stable mechanical characteristics even if a temperature environment changes in a range involving high temperatures to low temperatures.
The present invention has been accomplished in the light of the above-mentioned circumstances. It is an object of the present invention to provide a high durability cleaning blade member having excellent mechanical characteristics, such as wear resistance and resistance to edge drooping (edge drooping resistance), in any environment.